This application relates to a supplemental airflow passing over an oil cooler that typically receives air from a turbo fan in a gas turbine engine, with the supplemental airflow being actuated at times of low airflow from the turbo fan.
Gas turbine engines typically include a turbo fan, an ignition section and a turbine section. The turbine section drives the turbo fan, and also generates power for supplemental uses. One common use of such an engine is in jet aircraft.
The gas turbine engine is a very complicated piece of machinery involving a number of assemblies, components, etc. Many of these components must be provided with oil for lubricating and/or cooling purposes. Of course, this oil can become quite hot, and thus cooling the oil becomes necessary.
In known gas turbine engines, the oil is routed through a heat exchanger which is placed in the path of airflow driven by the turbo fan. While the gas turbine engine is operating, the turbo fan is driven, and air is driven through the heat exchanger for the oil cooler. However, at times during operation of the gas turbine engine the turbo fan is not being driven at a high rate and thus there is a lesser airflow over the heat exchanger. This can occur, for example, when an aircraft has just been shut down, is sitting on the runway for a period of time, at engine start-up, or other points of lower power to the turbo fan.